//Function to test if a character is alpha numeric that is faster than a regular
//expression in JavaScript

let isAlphaNumeric = ( char ) => {
  char = char.toString();
  let id = char.charCodeAt( 0 );
  if (
    !( id > 47 && id < 58 ) && // if not numeric(0-9)
    !( id > 64 && id < 91 ) && // if not letter(A-Z)
    !( id > 96 && id < 123 ) // if not letter(a-z)
  ) {
    return false;
  }
  return true;
};

console.log( isAlphaNumeric( "A" ) ); //true
console.log( isAlphaNumeric( 2 ) ); //true
console.log( isAlphaNumeric( "z" ) ); //true
console.log( isAlphaNumeric( " " ) ); //false
console.log( isAlphaNumeric( "!" ) ); //false
